Method for binding the filaments in an untwisted synthetic filament yarn



United States Patent 0 rm. 01.130311 11700,- cos 1/44 US. Cl. 16189 4 Claims ABSTRACT OF THE DISCLOSURE A method of manufacturing an untwisted synthetic filament yarn including the step of treating the wet-spun filaments utilized for preparing the yarn with a binding agent after the hot drying step and prior to the drying step. The invention also includes fabrics prepared from yarn manufactured according to the above-described process.

The present invention relates to a continuous process for binding the filaments of a continuous filament yarn. In weaving or knitting these filaments into various constructions, it has been found that, when the filaments are subjected to great frictional forces and tensions, such as arise in mechanical knitting and weaving operations, they tend to separate and become disheveled, giving rise to naps which not only make subsequent operations difficult but also result in yarn of reduced quality. Synthetic filaments, in particular, are so readily charged with static electricity they are spread open or disheveled quite frequently. To remedy this difficulty, it is conventional practice that, after the filaments have been dried and taken up on bobbins and prior to weaving or knitting, the filaments are twisted or heavily sized, because conventional antistatic treatment alone is not suificient to prevent opening or disheveling of the filament bundle and the consequent napping. However, as is well known in the art, twisting is a very costly process, while heavy sizing destroys the soft handling quality of fabrics.

It is a primary object of the present invention to provide a well-bound filament yarn which does not require twisting and/or sizing subsequent to drying and prior to weaving or knitting and which will not be disheveled or damaged during the subsequent weaving or knitting step. In accordance with this invention, Well-bound filament yarns may be manufactured by treating filaments with a binding agent, preferably, although not necessarily, in conjunction with the application of a lubricating agent such as finishing wax, or oil which treatment takes place after the drawing or relaxation step in the filament-manufacturing process and before the drying and take-up step. Thus, in the wet-spinning process, if the spun filaments are treated with a binding agent prior to drying, they no longer require twisting and sizing before being woven or knitted. In addition, since the filaments are in their wet-gel state, the binding agent may easily penetrate them uniformly. Accordingly, while previously in dry spinning or the melt-spinning processes, it had been found necessary to twist the filaments before the take-up step, followed by further twisting, sizing, drying, and waxing, it has now been found that these steps may be completely dispensed with by practising the process of the present invention.

The binding agent, and, if desired, lubricating agent may be applied to the filaments by dipping the filaments into separate aqueous solutions of the respective agents, or into a mixed aqueous solution containing both agents; alternatively, the filaments may be brought into contact Withseparate spongy elements carrying the respective aqueous solutions of the agents or a common spongy element carrying a mixed solution containing both agents. Another method is to drip a predetermined amount of said aqueous solutions or said mixed solution onto the travelling filaments.

The bound filaments are dried in a conventional manner, i.e., by the utilization of hot air streams or radiated heat, before being taken up by a bobbin. The lubricating agent, if employed, may be any agent that has heretofore been used for this purpose, such as long chain fatty esters of long chain fatty acids, preferably those containing from 10 to 25 carbon atoms, while the binding agent may be such materials as starches, alginates, polyvinyl alcohol, carboxymethylcellulose, or polyacrylate salts.

The preferred concentration of the binding agent in the mixed solution of said lubricating and binding agents ordinarily ranges from 2% to 15%, While the amount of the binding agent to be deposited on the filaments should range from 1% to 10% based on the weight of the latter, and preferably, from 2% to 7%. When the amount of said binding agent deposited on the filaments is less than 1%, no desired effect can be expected. On the other hand, if the amount exceeds 10%, the binding agent could present such difficulties as, for example, tending to adhere to the guides at subsequent steps in the process. The preferred amount of said lubricating agent to be deposited on the filaments ranges from 0.1% to 1.0%.

The filaments which are bound by said treatment may be immediately woven or knitted, bypassing the conventional sizing or twisting step. Moreover, since the thustreated filaments are not damaged or disheveled, the rewinding and twisting steps may be dispensed with and, accordingly, the possible defects due to uneven tension may be eliminated. The same effect may, of course, be obtained even when the binding treatment is not carried out concurrently with the finishing operation but rather is performed either before or after the finishing step, or even when the filaments are treated with the binding agent and dried before the surface of the bound filaments is treated with wax. As compared with the conventional filaments which must be sized just before the weaving or knitting step, the filaments of the present invention are not only more easily handled throughout the preparatory steps, but also the twisting and sizing operations may be dispensed with. Thus, if conventional filaments are sized, the damages arising from any preceding handling will still not be avoided. In accordance with the present invention, filaments may be effectively bound in the course of manufacture so that no separate treatment is required. Moreover, the present invention may be carried into practive by employing existing equipment.

The effect of the present method is particularly pronounced when the total denier of synthetic filaments and the denier of each monofilament are small.

The present invention will be further described by Way of the following examples.

Example 1 A copolymer composed of 91.2% acrylonitrile and 8.8% methyl acrylate is dissolved in 44% aqueous solution of sodium thiocyanate to prepare a spinning dope, the copolymer concentration of which is 11%. The dope is wet-spun into filaments in 5% aqueous solution of sodium thiocyanate through a spinnerette having 30 orifices of 0.08 mm. in diameter at the rate of 35.9 meters per minute, followed by washing with water. The fiber is then hot-drawn to 14 times its initial length in steam at 110 C. The filament is caused to travel in close contact with a sponge onto which an aqueous solution containing 40 g. of polyvinyl alcohol binder and g. of Zontes TA 460, a textile finishing oil which is manufactured by Matsumoto Oil & Fat, Ltd., of Japan, and which is the ethylenediamine derivative of stearic acid, in 1 liter of water is caused to drip at the rate of 4 g. per minute. Then, the filament is dried under tension on drying rollers at 110 C. and, further, caused to contact a hot plate at 180 C., whereby it is shrunken by 14%. The filament yarn is finally wound on a bobbin. The amount of the binder and lubricating oil were 4% and 1%, respectively, based on the weight of the yarn.

The filament yarn is d./30 filaments, having been well-bound by the above treatment. The filament yarn is virtually free from naps and broken filament in the subsequent preparatory step prior to weaving or knitting and the fabric woven out of the yarn has only a minimal nap and is substantially free from uneven weave. In contrast, the filament yarn treated with the finishing agent but not with the binding agent as above has to be twisted or sized in the conventional manner immediately before weaving. Otherwise, when it is rewound from the bobbin, the yarn tends to be disheveled and napped, proving highly prone to break. The fabric made of the yarn is also napped and uneven in mesh size. It is evidently lower in quality and saleability than a similar fabric made of the filament yarn of the present invention.

Example 2 The filament manufactured in the same manner as Example 1, using a spinnerette having 50 orifices of 0.06 mm. in diameter, is first washed with water and then hot-drawn to 14 times its initial length in steam at 115 C. The filament yarn is then caused to travel in contact with a sponge, onto which a binder solution of 12 g. polyvinyl alcohol and 8 g. sodium polyacrylate in 1 liter of water drips at the rate of 2 g. per minute. Then, the yarn is caused to run against a sponge, into which a finishing dispersion of 10 g. Derion 541, a textile finishing oil which is manufactured by Matsumoto Oil & Fat, Ltd., of Japan, consisting of mineral oil, 30% aliphatic ester, 20% polyalkyl ether, 2.5% alkylsulfonate and 2.5 polyoxyethylene alkylsulfonate, in 1 liter of water drips at the rate of 2 g. per minute. Finally, the yarn is dried under tension on drying rollers at 110 C. and a hot plate at 180 0, whereby the yarn is shrunken by 14%. The shrunken yarn is taken up by a bobbin. The amounts of deposition of said binder and finishing agent on the filament yarn are 2% and 1%, respectively, by weight. The resulting filament yarn is 40 d./ filament and has been well bound. The

4 Example 3 The filament manufactured by the same wet-spinning method as the one described in Example 1 is first drawn to 14 times its initial length in steam at C. and then passed through boiling water, whereby it is shrunken by 15%. The yarn is caused to run over sizing rollers supplied with a solution of 30 g. sodium polyacrylate binder in 1 liter of water and then dried under tension by means of drying rollers at C. The yarn is further treated with wax finish Sytex BIT-400 (Goya Chemical Co., Ltd.) and then wound on a bobbin. The amounts of deposition of said binder and wax finish on the filament yarn are 3% and 2%, respectively, by weight.

By virtue of the above-mentioned treatment, the filament yarn of this invention is well bound and the fabric made of the yarn is virtually free from napping and unand uneven weave.

What is claimed is:

1. In a method of manufacturing a substantially untwisted yarn composed of at least two filaments comprising the steps of wet-spinning said filaments, hot-drawing said filaments and drying said filaments, the improve-ment comprising treating said filaments with a binding agent selected from the group consisting of alginate salt, starch, polyvinyl alcohol, carboxymethylcellulose and sodium polyacrylate after said hot-drawing step and prior to said drying step.

2. A method according to claim 1 comprising treating said filaments with a lubricating agent selected from the group consisting of finishing wax and oil concurrent with or subsequent to said binding treatment with said binding agent.

3. An article comprising a knitted or a woven fabric prepared from yarn manufactured according to the method of claim 1.

4. An article comprising a knitted or a woven fabric prepared from yarn manufactured according to the method of claim 2.

References Cited UNITED STATES PATENTS 2,663,989 12/1953 Schlatter et al 57153 2,666,038 l/1954 Eisen 26023 2,693,429 11/1954 Radtke et a1 117126 X 3,117,888 1/1964 Fox 117-126 X 3,160,511 12/1964 Skeen et al. 1177 3,279,943 10/1966 Skeen et al 117139.5 X

WILLIAM D. MARTIN, Primary Examiner THEODORE G. DAVIS, Assistant Examiner US. or. X.R. 117 7, 139.5, 167 

